Bamfordite
A valid IMA mineral species
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About Bamfordite
Formula:
Fe3+Mo2O6(OH)3 · H2O
Colour:
Apple-green
Lustre:
Vitreous, Earthy
Hardness:
2 - 3
Specific Gravity:
3.620
Crystal System:
Triclinic
Name:
After its locality.
This page provides mineralogical data about Bamfordite.
Unique Identifiers
Mindat ID:
6815
Long-form identifier:
mindat:1:1:6815:0
IMA Classification of Bamfordite
Approved
IMA Formula:
Fe3+Mo6+2O6(OH)3·H2O
Approval year:
1996
Type description reference:
Birch, William D., Pring, Allan, McBriar, E. Maude, Gatehouse, Bryan M., McCammon, Catherine A. (1998) Bamfordite, Fe3+Mo2O6(OH)3·H2O, a new hydrated iron molybdenum oxyhydroxide from Queensland, Australia; description and crystal chemistry. American Mineralogist, 83 (1) 172-177 doi:10.2138/am-1998-1-218
Classification of Bamfordite
4.FK.05
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
K : Hydroxides with H2O +- (OH); chains of edge-sharing octahedra
4 : OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodates)
F : Hydroxides (without V or U)
K : Hydroxides with H2O +- (OH); chains of edge-sharing octahedra
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Bfd | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Bamfordite
Vitreous, Earthy
Transparency:
Transparent
Colour:
Apple-green
Streak:
Greenish yellow
Hardness:
2 - 3 on Mohs scale
Cleavage:
Distinct/Good
(100)
(100)
Comment:
Compact to friable in aggregates
Density:
3.620(8) g/cm3 (Measured) 3.616 g/cm3 (Calculated)
Optical Data of Bamfordite
Type:
Biaxial (-)
RI values:
nα = 1.91(1) nβ = 2.03(1) nγ = 2.11(1)
2V:
Measured: 90° , Calculated: 74°
Max. Birefringence:
δ = 0.200
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
r < v
Pleochroism:
Weak
Comments:
Pale to moderate; in yellowish greens
Chemistry of Bamfordite
Mindat Formula:
Fe3+Mo2O6(OH)3 · H2O
Element Weights:
Elements listed:
Crystallography of Bamfordite
Crystal System:
Triclinic
Class (H-M):
1 - Pinacoidal
Space Group:
P1
Cell Parameters:
a = 5.889(5) Å, b = 7.545(5) Å, c = 9.419(5) Å
α = 71.46(4)°, β = 83.42(4)°, γ = 72.78(4)°
α = 71.46(4)°, β = 83.42(4)°, γ = 72.78(4)°
Ratio:
a:b:c = 0.781 : 1 : 1.248
Unit Cell V:
378.91 ų (Calculated from Unit Cell)
Z:
2
Crystal Structure
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Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
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Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0001962 | Bamfordite | Birch W D, Pring A, McBriar E M, Gatehouse B M, McCammon C A (1998) Bamfordite, a new hydrated iron molybdenum oxyhydroxide from Queensland, Australia: Description and crystal chemistry American Mineralogist 83 172-177 |  | 1998 | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 3.319 Å | (100) |
| 3.232 Å | (90) |
| 5.620 Å | (70) |
| 4.095 Å | (70) |
| 4.711 Å | (50) |
| 2.614 Å | (50) |
| 1.956 Å | (50) |
Reference:
Birch, William D., Pring, Allan, McBriar, E. Maude, Gatehouse, Bryan M., McCammon, Catherine A. (1998) Bamfordite, Fe3+Mo2O6(OH)3·H2O, a new hydrated iron molybdenum oxyhydroxide from Queensland, Australia; description and crystal chemistry. American Mineralogist, 83 (1) 172-177 doi:10.2138/am-1998-1-218
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] |
Type Occurrence of Bamfordite
General Appearance of Type Material:
Apple green with yellowish tint
Place of Conservation of Type Material:
South Australian Museum, Adelaide, 20653; Museum of Victoria, Melbourne, Australia, M7424.
Geological Setting of Type Material:
Oxidation zone of greisen
Associated Minerals at Type Locality:
Reference:
Birch, William D., Pring, Allan, McBriar, E. Maude, Gatehouse, Bryan M., McCammon, Catherine A. (1998) Bamfordite, Fe3+Mo2O6(OH)3·H2O, a new hydrated iron molybdenum oxyhydroxide from Queensland, Australia; description and crystal chemistry. American Mineralogist, 83 (1) 172-177 doi:10.2138/am-1998-1-218
Synonyms of Bamfordite
Other Language Names for Bamfordite
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Bamfordite
mindat.org URL:
https://www.mindat.org/min-6815.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Bamfordite
Reference List:
Birch, William D., Pring, Allan, McBriar, E. Maude, Gatehouse, Bryan M., McCammon, Catherine A. (1998) Bamfordite, Fe3+Mo2O6(OH)3·H2O, a new hydrated iron molybdenum oxyhydroxide from Queensland, Australia; description and crystal chemistry. American Mineralogist, 83 (1) 172-177 doi:10.2138/am-1998-1-218
Localities for Bamfordite
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Australia (TL) | |
| Birch et al. (1998) |
Quick NavTopAbout BamforditeUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence SynonymsOther LanguagesOther InformationInternet Links References Localities Locality List
Bamford Hill Mines, Bamford, Mareeba Shire, Queensland, Australia